U.S. patent number 8,066,780 [Application Number 11/122,315] was granted by the patent office on 2011-11-29 for methods for gastric volume control.
This patent grant is currently assigned to Fulfillium, Inc.. Invention is credited to Richard Chen, Reinhold H. Dauskardt, Craig A. Johanson, Christopher S. Jones.
United States Patent |
8,066,780 |
Chen , et al. |
November 29, 2011 |
Methods for gastric volume control
Abstract
A gastric balloon includes a scaffold structure, one or more
internal inflatable compartments within the scaffold structure, and
one or more inflatable bladders formed over the space-filling
compartment. The gastric balloon may be deployed transesophageally
using a gastroscope and is inflated in situ, preferably using a
combination of liquid and gas inflation media.
Inventors: |
Chen; Richard (Napa, CA),
Johanson; Craig A. (San Francisco, CA), Jones; Christopher
S. (Menlo Park, CA), Dauskardt; Reinhold H. (Menlo Park,
CA) |
Assignee: |
Fulfillium, Inc. (Napa,
CA)
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Family
ID: |
35320703 |
Appl.
No.: |
11/122,315 |
Filed: |
May 3, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20050267595 A1 |
Dec 1, 2005 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60629800 |
Nov 19, 2004 |
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60567873 |
May 3, 2004 |
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Current U.S.
Class: |
623/23.65;
623/23.68; 600/37; 623/23.67; 600/116; 606/191; 606/192 |
Current CPC
Class: |
A61F
5/0036 (20130101); A61F 5/0033 (20130101); A61F
5/003 (20130101); A61M 2205/15 (20130101); A61M
2210/1053 (20130101) |
Current International
Class: |
A61F
2/04 (20060101) |
Field of
Search: |
;606/192,195,191
;623/23.65,23.67,23.68 ;600/37,116 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0103481 |
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Mar 1984 |
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EP |
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0246999 |
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Nov 1987 |
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EP |
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1177763 |
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Feb 2002 |
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EP |
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2090747 |
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Jul 1982 |
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GB |
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2139902 |
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Nov 1984 |
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GB |
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2384993 |
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Aug 2003 |
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GB |
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WO 83/02888 |
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Sep 1983 |
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WO |
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WO 87/00034 |
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Jan 1987 |
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WO |
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WO 88/00027 |
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Jan 1988 |
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WO |
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WO 03/055420 |
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Jul 2003 |
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WO |
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WO 03/095015 |
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Nov 2003 |
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WO |
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WO 2005/107641 |
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Nov 2005 |
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WO |
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Other References
International Search Report and Written Opinion of PCT Application
No. PCT/US05/41960, dated May 31, 2006, 4 pages total. cited by
other .
Supplementary European Search Report of EP Application No.
05749678, mailed on Oct. 2, 2009, 3 pages total. cited by
other.
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Primary Examiner: Jackson; Gary
Assistant Examiner: Mendoza; Michael
Attorney, Agent or Firm: Wilson Sonsini Goodrich &
Rosati
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application claims the benefit under 35 USC
.sctn.119(e) of prior provisional application No. 60/629,800, filed
on Nov. 19, 2004; and of prior provisional application No.
60/567,873, filed on May 3, 2004, the full disclosures of which are
incorporated herein by reference.
Claims
What is claimed is:
1. A method for treating obesity in a patient, said method
comprising: introducing a gastric balloon structure comprising a
scaffold and at least two inflatable space-filling compartments to
the inside of the patient's stomach; expanding the scaffold to
provide a fixed support geometry within the stomach; and at least
partly filling the at least two space-filling compartments of the
balloon with a compressible and/or incompressible fluid such that
the compartments are constrained by the scaffold after filling.
2. A method as in claim 1, further comprising determining the size
of the stomach and selecting a gastric balloon of a proper
size.
3. A method as in claim 2, wherein determining comprises visually
examining the gastric cavity of the stomach through a gastroscope,
externally scanning with X-rays, or externally scanning with
ultrasound.
4. A method as in claim 2, wherein the size is determined while the
stomach is filled with a biocompatible medium.
5. A method as in claim 4, wherein the balloon size is selected to
leave an unobstructed stomach volume surrounding the sides of the
device in the range from 10 cm3 to 100 cm3 after the balloon is
inflated.
6. A method as in claim 4, wherein the space-filling compartments
are filled with a mixture of compressible and incompressible fluid
to control the buoyancy of the gastric balloon in the stomach.
7. A method as in claim 6, wherein the mixture of compressible and
incompressible fluids is selected to provide a generally neutral
buoyancy in the stomach.
8. A method as in claim 1, wherein introducing comprises passing
the gastric balloon in a deflated configuration into the stomach
through a gastroscope or using an orogastric or nasogastric
tube.
9. A method as in claim 1, wherein the space-filling compartments
and/or the scaffold is/are configured so that the gastric balloon
structure will inflate with a curved geometry conforming to the
curve of the gastric cavity.
10. A method as in claim 1, wherein the at least two space-filling
compartments are inflated through an inflation tube removably
attached to the balloon.
11. A method as in claim 10, further comprising selectively
inflating each of the compartments by manipulating a valve
structure which directs inflation fluid to a selected
compartment.
12. A method as in claim 1, further comprising filling one or more
external bladders attached to or over the outer surfaces of the
space-filling compartments at least partially with a compressible
and/or incompressible fluid.
13. A method as in claim 1, further comprising deflating all of the
component structures and removing the deflated balloon from the
stomach.
14. A method as in claim 13, wherein deflating comprises breaching
one or more walls of each space-filling compartment.
15. A method as in claim 14, wherein breaching comprises severing a
common wall portion between two or more space-filling compartments
so that both deflate simultaneously.
16. A method as in claim 1, further comprising adjusting the fill
volume of at least one space-filling compartment after filling has
been completed.
17. A method as in claim 16, wherein fill volume adjusting
comprises reattaching an inflation tube to one or more
space-filling compartments, and filling or removing inflation fluid
through the reattached inflation tube.
18. A method as in claim 1, wherein said scaffold structure has an
interior and said space-filling compartments are constrained within
the interior.
19. A method as in claim 1, wherein the gastric balloon structure
floats free in the stomach after the scaffold is expanded and the
space-filling compartments are filled.
20. A method for deploying a gastric balloon structure in a
patient, said method comprising: introducing the balloon structure
to the patient's stomach; filling a scaffold structure to provide a
fixed support geometry; and separately filling a plurality of
isolated chambers within the scaffold structure, wherein the
chambers have individual volumes such that the collective volume of
the chambers remaining inflated after the deflation of any single
chamber is such that the balloon is prevented from passing through
the pyloric valve.
21. A method as in claim 20, further comprising detecting a
substance which is released into the stomach by a partially or
fully ruptured balloon chamber and is excreted, secreted, exhaled,
or regurgitated by the patient.
22. A method as in claim 21, wherein the substance is selected from
the group consisting of dyes, scented materials, symptom-inducing
agents, and detectable reactants.
23. A method as in claim 20, wherein at least some portions of the
balloon are inflated in situ by inducing a gas-generating reaction
within the balloon.
24. A method as in claim 20, wherein the scaffold structure has an
interior and said isolated chambers are constrained within the
interior after filling.
25. A method as in claim 20, wherein the gastric balloon structure
floats free in the stomach after the scaffold is expanded and the
space-filling compartments are filled.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to medical apparatus and
methods. More particularly, the present invention relates to the
construction and use of gastric balloons for treating obesity.
Obesity is a serious medical condition and has become a widespread
problem in the United States and many other industrialized
countries. While many obese patients may be treated by
modifications to diet and exercise, a number of morbidly obese
patients are resistant to treatment and are candidates for surgical
intervention. One surgical approach for treating morbid obesity is
referred to as gastric or jejunoileal bypass where a major portion
of the gastro-intestinal tract is surgically bypassed. While
effective in some patients, gastric bypass procedures can have
significant undesirable side affects. Moreover, the initial
surgical procedure presents risks associated with open surgery.
There are restrictive surgical procedures but they are less
effective and still invasive. Consequently, an effective,
non-invasive medical treatment with lower risks and minimal side
effects is needed for many morbidly obese patients, who cannot
tolerate surgical intervention, and most premorbidly obese
patients, who have no effective treatment because their condition
is not sufficiently severe to qualify them as surgical
candidates.
As an alternative to such surgical procedures, the introduction of
space-occupying structures into the stomach, often referred to as
"gastric balloons," has been proposed. Such gastric balloons may be
introduced through the esophagus and inflated in situ in order to
occupy a significant volume within the stomach.
Although found to be effective in some cases, the use of gastric
balloons has been compromised by a number of deficiencies. The most
serious is a sudden or slow deflation of the gastric balloon that
can allow the balloon to pass the pyloric valve and enter the
intestines. Such unintentional passage of the deflated balloon into
the intestines can cause intestinal obstruction and be
life-threatening. Consequently, gastric balloons currently marketed
outside the US are generally indicated for use of only up to six
months.
The risk of deflation is exacerbated by the fact that the patient
may not immediately be aware that the balloon has deflated,
delaying the patient from seeing a physician. Thus, it would be
desirable to provide approaches to allow a patient to detect
leakage or impending leakage. Currently to detect leakage, some
practitioners add methylene blue dye to the filling fluid, usually
saline, prior to inflation. If the methylene blue leaks into the
stomach, a blue color will be present in the patient's excrement.
This procedure has a number of deficiencies as evidenced by the
continued reports of significant rates of intestinal obstruction
and excretion of deflated balloons in clinical practice. Slow and
intermittent leaks can release such small amounts of dye that the
dye is not detectable in the excrement. Faults on the medical
professionals' part include mixing concentrations that makes
detection unreliable or simply forgetting to mix in the substance
prior to inflating the balloon. On the patients' side, many have
difficulties detecting slight changes in the color of the
excrement, forget to check diligently, or simply find the task
psychologically too unpleasant to perform.
Other problems include infections resulting from bacterial
colonization of the gastric balloon and lack of adequate sizing of
the balloon prior to deployment in a patient's stomach.
Additionally, most gastric balloons have been filled with saline or
other liquid, making them heavy and uncomfortable within a
patient's stomach. The weight of the balloons can cause them to
induce gastric hypertrophy and create gastric erosions, ulcers,
lesions and abrasions within the stomach at the points where they
naturally rest.
For these reasons, it would be desirable to provide improved
gastric balloon structures and methods for their use in treating
obese patients. The balloons should be durable and the methods and
apparatus will preferably be comfortable to the patient and in
particular should avoid settling as a heavy weight in the patient's
stomach. The gastric balloons and methods for their use should
further prevent passage of an accidentally deflated balloon across
the pyloric valve and into the intestines, even when the balloon
structure is compromised and the balloon looses inflation medium.
It would be further desirable if a deflation or impending deflation
of the balloon were detectable to the patient in a rapid and
reliable fashion. Such a detection system should alert the patient
of failure and allow the patient to seek medical help before the
balloon has deflated to a size that could pass the pylorus. The
compromised device could be then removed or replaced on a timely
basis. Additionally, it would be beneficial if the balloons were
resistant to bacterial and other microbial growth, thus lessening
the risk of infection upon long-term deployment. Other improvements
would include balloons and methods for their deployment which allow
for proper sizing the balloon and/or trimming or adjusting the
balloon size even after deployment. At least some of these
objectives will be met by the inventions described below.
2. Description of the Background Art
Gastric balloons and methods for their use in treating obesity are
described in U.S. Pat. Nos. 6,746,460; 6,736,793; 6,733,512;
6,656,194; 6,579,301; 6,454,785; 5,993,473; 5,259,399; 5,234,454;
5,084,061; 4,908,011; 4,899,747; 4,739,758; 4,723,893; 4,694,827;
4,648,383; 4,607,618; 4,501,264; 4,485,805; 4,416,267; 4,246,893;
4,133,315; 3,055,371; and 3,046,988 and in the following
publications: U.S. 2004/0186503; U.S. 2004/0186502; U.S.
2004/0106899; U.S. 2004/0059289; U.S. 2003/0171768; U.S.
2002/0055757; WO 03/095015; WO88/00027; WO87/00034; WO83/02888; EP
0103481; EP0246999; GB2090747; and GB2139902.
BRIEF SUMMARY OF THE INVENTION
The present invention provides improved gastric balloons and
methods for their deployment and use. The balloons will typically
have an overall volume or displacement selected to leave a residual
volume in the proximal area of the stomach in the range from 10 ml
to 100 ml, usually from 20 ml to 40 ml. As discussed in detail
below in some embodiments, the volume will be adjustable to
optimize treatment on individual patients. The gastric balloons
will typically be designed to conform to the natural shape of the
gastric cavity while maintaining the normal function of the
stomach. The balloon will preferably have a crescent or "kidney"
shape to align the balloon wall against the greater and lesser
curvatures of the stomach, an oval cross section to conform to the
shape of the cavity in the sagittal plane, and delineate a space
proximally for the collection of ingested food and another space
distally for active digestion.
The gastric balloons include at least two principal structural
components. The first principal structural component is an
expandable scaffold which helps define a shape conforming to a
gastric cavity, typically a crescent or "kidney" shape, when
expanded. The scaffold may be self-expanding, e.g. formed from a
shape memory metal or shape memory polymer, or may be inflatable
with an incompressible fluid, such as saline, water, oil, gel, or
other liquid, gel, slurry, solution, or the like. Use of an
incompressible inflation or filling fluid helps rigidify the
scaffold so that it maintains its shape for extended periods when
implanted in the stomach. The expanded shape and side of the
scaffold by itself or together with an intact portion of the device
form an object that is too large in all orientations, even when
compressed in peristalsis, to permit the device to pass the
pylorus.
The second principal structural component comprises one or more
inflatable or otherwise expandable space-occupying structures or
compartments which are secured to the interior and/or exterior of
the expandable scaffold. The space-filling structures or
compartments assume a space-filling configuration when inflated or
otherwise filled or expanded, typically being inflated or filled at
least partly with a compressible fluid, typically a gas such as
air. Such filling or inflation of the scaffold and/or the
space-filling compartment(s) will usually be accomplished from an
external pressurized fluid source, but certain gaseous inflation
media can be generated in situ within the component by chemical
reactions induced by mixing reactants or otherwise initiating a
gas-producing chemical reaction. In some cases, the scaffold may
form all or a portion of the space-filling structure or
compartment.
The scaffold and the inflatable compartment(s) may be joined
together in a number of different ways. Self-expanding scaffolds
may be disposed inside of, within, or over the walls of the
inflatable compartment(s). The scaffolds may have a number of
different geometries, including spines, hoops, serpentine elements,
plates, shells, or the like. In one particular embodiment, a
self-expanding scaffold comprises a single spine which runs axially
along one side of the inflatable compartment(s) with a number of
generally oval rib structures extending circumferentially around
the inflatable compartment(s). In another specific example, the
self-expanding scaffold may be in the form of a plurality of
interleaved panels which form an umbrella-like cap on one end of
the scaffold, typically the end disposed adjacent to the esophagus
after deployment. In still another example, the expandable scaffold
may be an inflatable saddle or shell which is attached over an
outer surface of one or more inflatable compartment(s). In still
other embodiments, the scaffold structure may be formed internally
with two or more inflatable compartments disposed on the outside of
the structure. For example, in a particular embodiment, the
scaffold is inflatable and forms an X-shaped cross section with
four inflatable compartments, one in each quadrant of the X.
Numerous other particular configurations may be made within the
principles of the present invention.
The gastric balloons of the present invention may comprise two or
more walls or layers or lamina of materials to improve the
durability of the device by optimizing the performance
characteristics of different materials. This is desirable because
the maximal thickness of the entire device in its deflated state
such that it can be passed uneventfully through the esophagus is
limited and is useful even for a simple, single compartment
balloon. Typically, the outermost layer is made of materials, such
as silicone rubber, selected primarily for their biocompatibility
in the stomach and resistance to an acidic environment and the
innermost layer is made of materials selected primarily for their
resistance to structural fatigue and permeability to the filling
fluid. In addition, use of multiple layers allows the layers to be
formed from different materials having different properties, to
enhance the performance characteristics of the entire balloon
structure. The inner layers could have biocompatibility of a
shorter duration than the outermost layer. It may be desirable to
enhance the durability further by embedding other structural
elements in the layers, such as a mesh made of metal, polymer, or
high strength fibers, such as Kevlar.RTM.. In the simplest
embodiment, the two layers are either bonded together to function
as a single wall or left unbonded such that the layers could slide
by each other except at certain attachment points.
Optionally, a variety of structural elements may reside in between
the outermost and innermost layers. For support, the mesh of high
strength fibers, polymer, or metal could constitute another layer
in of itself instead of being embedded in the layers.
Alternatively, the mesh forms or is a component of the expandable
scaffold. One or more layers of materials selected for the optimal
balance of biocompatibility, impermeability, rigidity, durability
among other criteria could be added to enhance the structural
performance characteristics of the device further.
Optionally, a failure detection system may reside in between any of
the layers. This is desirable and useful even for a single
compartment balloon. An example of a chemical system is based on a
thin film or coating of a substance, such as a dye, that is
released into the stomach in the event the integrity of the layer
external to the substance is compromised and detected upon
excretion or regurgitation by the patient. Optionally, different
substances may be placed in between different layers so that the
particular layer which failed may be identified based on what is
detected. Optionally, the substance could be embedded in the layer
so that partial breach of the layer would result in the substance
be in contact with the stomach contents. Incorporating the
substance(s) in the device eliminates a step for the medical
professional to measure and mix the substance(s) into the inflation
media. Many errors including mixing ineffective concentrations such
that detection becomes unreliable, contaminating the different
components such that identification of the particular failed
component becomes unreliable, confusing the substance(s) with its
respective component, or simply forgetting to mix in the
substance(s) are prevented. Furthermore, the detection mechanism is
standardized for the device and easier for medical professionals
other than the person deploying the device to diagnose any
failure.
The inflatable compartment(s) may be inflated with compressible
fluids (gases), incompressible fluids (liquids), or in some cases
mixtures of gases and liquids. When multiple inflatable
compartments are used, each compartment may be inflated with the
same or different gas(es), liquid(s), and/or mixtures thereof. The
use of gas and liquid for gastric balloon inflation has a number of
advantages. A principal benefit is the ability to control buoyancy
and weight distribution within the balloon, e.g., by filling most
of the compartments with a gas and distributing the non-gas
inflation medium in other compartments throughout the balloon, the
risk of concentrated pressure points against the stomach is
reduced. Second, by properly controlling the ratio of air or other
gas to saline or other liquid, the gastric balloon can be provided
with a desired buoyancy and mass within the stomach. Typically, the
ratio of air:liquid can be in the range from 2:1 to 10:1, more
preferably within the range from 3:1 to 6:1. Such ratios can
provide effective densities relative to water at a specific gravity
in the range from 0.09 to 0.5, usually from 0.17 to 0.33, depending
on the total volume occupied by the device. Typically, the weight
of the filled balloon is in the range from 50 gm to 500 gm, usually
being from 50 gm to 450 gm. The use of gastric balloons which are
light and less dense will reduce the risk that the balloons will
cause abrasion, pressure induced lesions, shearing lesions, or
other trauma when implanted in the stomach for extended periods of
time.
Optionally, the gastric balloons of the present invention may
further comprise at least one separately inflatable or otherwise
expandable external bladder formed over an exterior surface of the
balloon. The external bladder(s) will be separately inflatable from
both the scaffold and the space-filling compartment(s) although
they may be attached to or share common walls with either or both
of these other principal structural components. The bladder will be
positioned on the exterior of the balloon so that it can control
either or both of the shape and buoyancy of the balloon as a whole.
Typically, the bladder will be inflated at least partly with a
compressible gas, typically air or other biocompatible gas. Often,
the balloon will be underfilled, i.e., filled with a volume that
does not distend or increase the wall tension beyond that of the
unfilled bladder.
The expandable scaffold, the inflatable space-filling
compartment(s) or structures, and optionally the inflatable
bladder(s) may be joined together in the overall gastric balloon
structure in a variety of ways. Typically, each component may be
separately formed and joined by adhesives, bonding, or by other
non-penetrating fasteners, or by other means. Alternatively, all or
a portion of these principal structural components may be formed by
co-extrusion to provide the desired inflatable volumes. Generally,
however, it will be desirable to avoid penetrating fasteners and/or
stitching of the principal structural components since such
penetrations can compromise the integrity of the components and
subject the balloon to leakage over time.
The expandable scaffold upon self-compression or inflation may
define one or more internal regions or volumes which receive the
inflatable compartment(s). In a first exemplary illustrated
embodiment, the scaffold when inflated has a X-shaped cross-section
which defines four axially aligned quadrants or channels which
would allow relatively free passage of food past the scaffold and
through the stomach in the absence of the inflated internal
component(s). The inflatable scaffold will usually be formed from a
non-distensible material so that it can be fully and generally
rigidly inflated by the liquid or other incompressible fluid. The
internal components, in contrast, may be formed from an elastic
and/or inelastic material to permit its volume to be differentially
inflated and adjusted. Usually, the space-filling compartment(s)
will leave at least a portion of the channels available for the
passage of food, albeit in a restricted or modulated fashion.
Alternatively, the shape and structure of the entire device could
allow ingested food to pass between the exterior and the stomach
wall.
Alternatively, the scaffold could comprise a metal or polymeric
scaffold or other open structure which supports the other balloon
components but which is not itself inflatable. For example, an open
lattice formed from a shape memory material, such as a
nickel-titanium alloy, can be compressed and constrained together
with the inflatable components for delivering to the stomach. The
structure can be self-expanding, i.e. deployed by being released
from constraint after delivery to the stomach so that the lattice
opens to its memory shape. Such self-expanding scaffolds are
preferably collapsible under restraint to a relatively low-profile
configuration, typically having a width no greater than about 30
mm, preferably no greater than about 20 mm, in order to permit
delivery through a gastroscope or other tubular introducer
positioned through the esophagus. For example, the lattice could
comprise or consist of one or more axial members having hoop, loop,
or rib elements attached along their length(s). Alternatively, the
lattice could comprise a plurality of interleaved panels which
could be folded and/or rolled into a low width configuration. Other
examples include collapsible meshes, collapsible coils, malecot
structures, and the like. In contrast, the inflatable components
will be deflated to permit introduction in a low profile
configuration. The inflatable components can have a variety of
geometries including X-shaped cores, inflatable saddles, inflatable
caps, and the like. The inflatable components can be deployed by
inflation as described elsewhere herein. Alternatively, in some
instances, the scaffold might be an outer shell or "exo-skeleton,"
in some cases simply being a non-distensible sheath or cover which
permits inflation of two or more inflatable compartments therein.
Still further alternatively, the scaffold may be formed of a solid
material for the attachment of the other components of the device
in a particular configuration such that collectively, the
components assume the desired physical shape or perform the desired
functions.
The external bladder(s) may also be formed from elastic and/or
inelastic materials, such as silicone rubber and polyethylene
terephthalate film (Mylar.RTM.), respectively, so that they can be
inflated at the end of the procedure to properly position the
gastric balloon within the stomach and to provide for proper sizing
of the balloon within the stomach. In an illustrated embodiment,
the gastric balloon includes one space-filling compartment and one
external bladder for each of the four channels formed by the
inflatable scaffold, but the number of compartments and/or bladders
may differ from the number of channels.
Most embodiments of the present invention will include at least two
or more inflatable-space-filling compartments and in some cases may
also include one or more inflatable external bladders. The
inflation of multiple inflatable compartments and external bladders
may be accomplished in a variety of ways. Most simply, each
inflatable compartment and inflatable external bladder (if any)
could be connected to an independent inflation tube which can be
disconnected after inflation. The use of multiple independent
inflation tubes allows each inflatable compartment and external
bladder to be selectively and independently filled, further
allowing filling at different pressures, with different inflation
fluids, and the like. The use of multiple inflation tubes, however,
is not generally preferred since the tubes, collectively, can have
rather a large cross section, and such multiple tubes may interfere
with device deployment.
The multiple inflatable compartments and external bladders of the
present invention may be filled through a single inflation tube in
at least two ways. First, by connecting the inflatable compartments
and external bladders in series, for example using a series of
one-way valves, inflation through a first inflatable compartment
(or external bladder) can sequentially fill additional compartments
and bladders in the series as the pressure in each compartment
raises and in turn begins to fill the next compartment or bladder
in series. Such an approach, however, is generally less preferred
since it does not permit selective filling of the compartments and
therefore does not permit the pressure and/or composition of the
inflation fluid to be controlled and differentiated between the
multiple compartments.
Thus, a presently preferred structure and method for filling the
multiple compartments and external bladders (if any) of the present
invention is to use a selective valve system which can be accessed
and controlled by a single inflation tube in order to independently
and selectively inflate each of the inflatable compartments and
external bladders (if any). Such selective valving system may be
constructed in any of at least several ways. For example, an
inflation tube having a lateral inflation port near its distal end
can be disposed between two, three, or more one-way valves opening
into respective inflatable compartments and external bladders. By
rotating the inflation tube, the inflation port on the tube can be
aligned with one of the one-way valves at a time, thus permitting
inflation of the respective compartment or bladder to a desired
pressure and with a desired inflation fluid, including liquid
inflation fluids, gaseous inflation fluids, and mixtures thereof.
The rotatable and selectable inflation tube could be removable.
Alternatively, at least a portion of the inflation tube could be
permanently mounted within the gastric balloon structure, allowing
an external portion of the inflation tube to be removably coupled
to the internal portion to deliver the inflation fluids.
In addition to rotatably selectable inflation tubes, the inflation
tube could be axially positionable to access linearly spaced-apart
one-way valve structures, each of which is connected to a different
inflatable compartment or external bladder.
As a still further alternative, a single inflation tube could be
rotatably mounted and have several inflation ports along its
lengths. Each of the inflation ports could be disposed near one,
two, or more different one-way valves communicating with different
inflatable compartments and/or external bladders.
In all these cases, the one-way valves will permit inflation by
introducing an inflation medium at a pressure sufficiently high to
open the one-way valve and permit flow into the associated
inflatable compartment or external bladder. Upon removing the
pressurized inflation source, the one-way valve will close and
remain sealed in response to the increased pressure within the
inflatable compartment or external bladder.
In all cases, the inflation tube(s) will be removable from the
connected component after the component or multiple components have
been inflated. Thus, as described in more detail below, the gastric
balloon may be delivered to the stomach in a deflated, low profile
configuration, typically through a gastroscope or other
transesophageal delivery device. Once in place, the expandable
scaffold may be deployed and the inflatable components may be
inflated, filled, or otherwise expanded in situ to a desired volume
and buoyancy typically by delivering the inflation media through
the inflation tubes.
Once the desired inflation size is reached, the inflation tubes may
be detached from each of the compartments allowing self-sealing so
that the inflation medium remains contained for extended periods of
time. To ensure the containment of the medium, valves may be placed
in series for any one or more of the inflatable component(s) and/or
bladder(s). Other expansion protocols are described elsewhere
herein. In particular, component, compartment, or portion of the
balloon may be inflated in situ by inducing a gas-generating
reduction within the balloon. The reactant(s) may be present in the
balloon prior to introduction to the patient or may be introduced
using the connecting tubes after introduction to the stomach.
Although one illustrated embodiment of the present invention
includes four channels in the inflatable scaffold, it will be
appreciated that the present invention will cover gastric balloon
structures having only a single passage or channel formed within
the scaffold with a single space-filling compartment and single
external bladder. Embodiments with two channels, space-filling
compartments and external bladders as well as three channels, three
space-filling compartments, and three external bladders, as well as
even higher numbers will also be within the scope of the present
invention.
The dimensions of the scaffold, space-filling compartment(s) or
structure(s), external bladder(s), and/or isolated inflation
chambers within any or all of these components, will be selected
such that the collective volume or physical dimensions of the
chambers remaining inflated after deflation of any single chamber
(or limited number of chambers) is sufficient to prevent passage of
the balloon through the pyloric valve. Usually, the volume(s) will
be such that at least two inflatable components and/or chambers
within said components could deflate without risk of the
"diminished" balloon passing through the pyloric valve, preferably
at least three could deflate, and often at least four or more
chambers could deflate. The precise volume(s) necessary to prevent
passage of the partially deflated balloon structure through the
pyloric valve and may vary from individual to individual. A
preferred remaining residual inflated volume will be at least about
75 ml, preferably at least about 100 ml and still more preferably
at least about 200 ml. After partial deflation, the balloon should
have a dimension along any axis or its cross axis of at least 2 cm,
preferably at least 4 cm, and most preferably at least 5 cm.
Should any of the principal structural components or any portion(s)
thereof fail, then the present invention optionally provides for
failure detection. This is desirable and useful even for a single
compartment balloon. For example, a substance may be disposed
within any or all (at least one) of the internal volumes of the
inflatable scaffold, the inflatable space-occupying component(s),
and/or the external bladder (or any chambers therein), where the
substance is detectable upon release and excretion or regurgitation
by the patient. For example, the substance may be a dye, a scented
composition, a benign symptom-inducing agent such as polyvinyl
pyrolidine (PVP), or the like. The substance will usually be
disposed within each of the inflatable volumes of the scaffold,
space-occupying compartment, and the external bladder so that
failure of any single component or chamber thereof will be
provided. Optionally, different substances may be placed in
different components so that the particular component which failed
may be identified based on what is detected. The substance may be
detectable directly by sight, smell, or sensation, and/or by
reaction with water in the toilet optionally with the addition of a
detection reagent.
A particular failure detection system according to the present
invention for gastric balloons comprises a chemical and a chemical
vapor detector. Optionally, the system includes at least one other
chemical or biochemical that reacts with the chemical, its
metabolite, or its reaction product. While this invention is
described being used in conjunction with a gastric balloon, it does
not exclude use in other biomedical devices where signaling a
potential failure or malfunction, especially those potentially
leading to a catastrophic loss, is desired. The chemical is
disposed in a structural component or in an enclosed volume of the
device but released into the body upon a breach in the integrity of
the device. After release, the chemical, either in its stable form,
metabolite, or reaction product is eventually secreted or excreted
into the bodily fluids or exhaled gases. The chemical, its
metabolite, or reaction product is sufficiently volatile in its
secreted or excreted form so that the vapor concentration is
significant enough to be detected by a sensor. Optionally, the
system could be improved by subjecting the chemical, its
metabolite, or reaction product to certain physical perturbation,
such as heat or sonic waves, such that the vapor concentration is
altered. Alternatively, the system could be improved through a
reaction where the chemical, its metabolite, or reaction product is
mixed with other chemicals or biochemicals, including solvents,
resulting in a product whose vapor concentration has changed enough
to be detected by a sensor. Once the sensor is triggered, a signal
indicating the compromised state of the device is sent in order to
seek medical assistance on a timely basis. The system requires
minimal motivation and judgment in diagnosis and enables detecting
device failure in a more consistent and reliable fashion at home.
The task of checking one's excrement is thereby avoided.
The chemical could be naturally occurring, synthetic, or made by
the human body. Preferably, it is biocompatible to the human body
at the concentration that would result if the amount disposed in
the device is released completely in one event. Upon such an event,
for example, a tear or break in a component, the chemical is
released into direct contact with the contents of the body cavity,
surrounding tissues or their secretions. It is then absorbed and
secreted or excreted in the body fluids or exhaled gases in its
stable form. Alternatively, the chemical is metabolized by the body
and its metabolites are secreted or excreted in the body fluids.
Alternatively, the chemical or its metabolites react with the
contents of the body cavity, surrounding tissues or their
secretions, or any part of the body until the reactant products are
secreted or excreted. The change in vapor concentration of the
chemical, its metabolites, and/or reactant products is then
detected by the sensor.
Alternatively, more than one chemical could be disposed separately
or together as a mixture in the device. After release, the
chemicals are then absorbed and secreted or excreted in the body
fluids or exhaled gases in their stable forms. Alternatively, at
least one of the chemicals is metabolized by the body and its
metabolites are secreted or excreted in the body fluids or exhaled
gases and the others could have a separate functions, such as a
stabilizing agent or catalyst. Alternatively, at least one of the
chemicals reacts with the contents of the body cavity, surrounding
tissues or their secretions or any part of the body until the
ultimate reactant products are secreted or excreted. Alternatively,
at least one of the chemicals or its metabolites or reactant
products react with each other in the presence of the contents of
the body cavity, surrounding tissues or their secretions or any
part of the body until the ultimate reactant products are secreted
or excreted. At least one of the products of the reaction is then
secreted or excreted in its stable form or as metabolites in the
body fluids or exhaled gases. Used as a mixture, the change in
vapor concentration of one or more of the chemicals, their
metabolites, or their reaction products could be more readily
detected to increase sensitivity of the detection system or the
change in vapor concentration of more than one increases the
specificity.
Optionally, more than one chemical or more than one mixture of
chemicals may be disposed in different parts or components in the
device so that more than one part or component which has been
compromised may be identified based on which chemical was
detected.
Optionally, more than one chemical or more than one mixture of
chemicals may be disposed in the same part or component in the
device so that the degree of compromise may be determined based on
which chemical or a combination of chemicals was detected.
The chemical or mixture of chemicals can be disposed anywhere in
the device or its components but typically in the wall of the
balloon or any part that is more likely to be compromised. It can
be distributed evenly throughout the structure or in an irregular
fashion but preferably widely enough to cover the potential sites
of failure. The preferred configuration is a fine lattice or
continuous film of the chemical or chemical mixture embedded in the
wall or in between layers of the wall covering the entire balloon,
thereby conforming to the shape of the balloon. Such a
configuration optimizes the performance of the system in detecting
failures early. As the site of the breach cannot be predicted, a
breach is unlikely to be missed by covering the entire balloon.
Compromise of the balloon typically starts with a somewhat linear
split or tear in surface of the balloon wall from mechanical
fatigue. As the split propagates, it will soon expose more and more
lines of the lattice or area of the film to the stomach contents.
Consequently, as the size and seriousness of the breach increases,
the more the chemical is released and the probability of detection
increases. Being embedded in the wall of the balloon further
enables detection before a full breach of the entire thickness of
the balloon wall.
Optionally, the performance could be enhanced by subjecting the
chemical, its metabolite, or reactant product to certain physical
perturbation, such as heat or sonic waves, such that the vapor
concentration is altered. For example, the vapor concentration
could be increased in a well heated room or by a toilet flush.
Alternatively, the system could be enabled through a reaction where
the chemical, its metabolite, or reactant product is mixed with
other chemicals or biochemicals (which need not be biocompatible)
introduced exogenously and the vapor concentration of the exogenous
reaction product is detected by the sensor. For example, a supply
of the exogenous chemical can be packaged like a solid toilet bowl
cleaner and placed in the water tank. The chemical is dispensed
consistently and reliably as a reactant into the bowl. The reaction
product in the resulting concentration is at a level necessary for
detection but could be bioincompatible had the reaction occurred in
the body.
The chemical vapor detector is based on either the natural
olfactory sense or the commercially available technology of
so-called "electronic nose", with which certain chemicals can be
detected at levels from parts per million to parts per billion. The
detector is preferably powered by batteries and portable enough to
be worn on a wristband or belt or can be placed conveniently near
the toilet. Upon sensing the chemical, its metabolite, or the
reaction product, the detector will alert the patient to seek
medical assistance or alert medical professionals directly through
other devices, such as Bluetooth linked to an autodial telephone.
The alarm could be auditory, such as beeping sounds, visual, such
as flashing LED's or a LCD display, sensory, such as vibrations, or
preferably a combination of any or all of the above. Optionally,
the detector could have different auditory, visual, sensory, or
different combinations to identify the source of the detected
breach, especially with more than one chemical is used. For
example, LED's of different colors or different sounds could be
used. The alarm could further indicate the seriousness of the
breach. For example, when multiple probes detect a breach, the
volume of the alarm would increase to a higher level.
The present invention further provides a wireless failure detection
system for gastric balloons and methods for their deployment and
use. While this invention is described being used in conjunction
with a gastric balloon, it does not exclude use in other biomedical
devices where signaling a potential failure or malfunction,
especially those potentially leading to a catastrophic loss, is
desired. The failure detection system comprises two probes, a
wireless transmitter, and a wireless detector. While this invention
is described using radio frequency as the signal transmission of
choice, it does not exclude other carrier waves, such as light or
acoustic, or via physical properties, such as magnetism or
temperature. The probes are connected electronically to the
wireless transmitter, which can emit a signal recognized by the
detector. Upon direct contact with the stomach contents by the
probes, the transmitter is enabled to signal the detector to notify
the patient that the integrity of the balloon is compromised and,
therefore, seek medical assistance. The system requires minimal
motivation and judgment in diagnosis and enables detecting device
failure in a more consistent and reliable fashion at home. The task
of checking one's excrement is thereby avoided. The system can be
designed to function in a variety of algorithms to notify the
patient in a simple, unequivocal fashion. For example, in a toggle
algorithm, the transmitter is either on in the static state or
preferably off in order to reduce the need for power. Upon direct
contact with the stomach contents, the probe causes the transmitter
to turn the signal off or preferably on to be able to send a
wireless signal on a continuous basis. The wireless signal or lack
thereof is recognized by the detector to notify the patient that
the integrity of the balloon is compromised.
Alternatively, the algorithm could be based on time, amplitude,
frequency, or some other parameter. For example, the transmitter
may send a wireless signal at a predetermined time interval in its
static state. The detector recognizes the length of the interval as
normal and the existence of the signal as the system in working
order. Upon direct contact with the stomach contents by the probes,
the transmitter is enabled to send the same signal at different
time intervals or a different signal, which is recognized by the
detector to notify the patient that the integrity of the balloon is
compromised. The lack of a signal is recognized by the detector to
notify the patient of a detection system malfunction and potential
compromise of the integrity of the balloon.
Optionally, more than one probe or more than one type of probe may
be placed internally in different parts or components in the device
so that the particular part or component which failed may be
identified based on which probe was activated. The transmitter
would send different signals for the receiver to display the source
of the failure.
The internal probe could be of any shape and is disposed in the
interior or preferably in the wall of the balloon. The preferred
configuration is a fine lattice or continuous film of the detection
material embedded in the wall or in between layers of the wall
covering the entire balloon, thereby conforming to the shape of the
balloon. Such a configuration optimizes the performance of the
system in detecting failures early. As the site of the breach
cannot be predicted, the probe would be unlikely to miss detecting
the breach by covering the entire balloon. Compromise of the
balloon typically starts with a somewhat linear split or tear in
surface of the balloon wall from mechanical fatigue. As the split
propagates, it will soon expose more and more lines of the lattice
or area of the film to the stomach contents. Consequently, as the
size and seriousness of the breach increases, the probability of
detection increases. Being embedded in the wall of the balloon
further enables detection before a full breach of the entire
thickness of the balloon wall. There are further advantages. As the
size of the balloon that can pass uneventfully through the
esophagus is limited, typically no larger than 2 cm in diameter in
its deflated cylindrical shape, the volume of detection material
per area of balloon wall is reduced. Furthermore, the lattice or
film could provide additional structural support to the device.
The detection material could be any metal, polymer, fiber, or
combination thereof, with or without any coating that can generate
an electrical charge or enable flow of electric current when in
contact with the stomach contents. For example, an electrical
charge could be generated from a non-toxic chemical reaction when
the lattice exposed underneath a tear comes in contact with the
acidic contents. Flow of electric current could be enabled when two
ends of an electric circuit are in contact with electrolytes in the
stomach. For example, a charged lattice is embedded in the wall and
the ground is the external probe on the surface of the balloon or
the lattice is ground and the probe is charged. When the lattice is
exposed to the electrolytes in the stomach content, the circuit is
closed. Alternatively, the lattice and ground could be separate
from each other but interlaced in the wall of the device. Preferred
materials include non-corrosive, biocompatible metals and
elastomers containing electrically conductive particles.
The transmitter can be a simple wireless signal generator triggered
by an electric current or preferably a transponder using the
well-established RFID technology, i.e., produces a wireless signal
when triggered by an interrogating signal. The electric charge
generated or the electric current enabled by the probe in contact
with the stomach contents enables the transmitter to emit or causes
it to emit a wireless signal. Typically, the transponder is powered
by the interrogating radio frequency signal so that no power source
of its own is required. Alternatively, the transmitter could be
powered by a micro battery or by the electrical power generated by
a chemical reaction. For protection from degradation by an acidic
and electrolyte solution and become potentially toxic, the
transmitter or transponder circuit is encased in a highly resistant
material, such as silicon rubber or stainless steel. The
transmitter or transponder circuit can be placed on the exterior,
embedded in the wall, or preferably in the interior of the balloon
for further shielding from chemical degradation and mechanical
stress. It can be placed in any orientation, preferably in the
plane where the antenna is most sensitive and the transmitter is
most effective in sending and receiving signals through body
tissue.
The wireless signal from the transmitter is recognized by a
detector external to the body. The detector could be simply a
receiver tuned to the transmitter's signal or, preferably, a
combination of both a transmitter of a signal to interrogate the
transponder and a receiver to distinguish the different signals
from the transponder. The detector is preferably powered by
batteries and portable enough to be worn on a wristband or belt or
can be placed conveniently near a place where the patient spends
most of his time. Upon receiving a signal that a breach has
occurred, the detector will alert the patient to seek medical
assistance or alert medical professionals directly through other
devices, such as Bluetooth linked to an autodial telephone. The
alarm could be auditory, such as beeping sounds, visual, such as
flashing LED's or a LCD display, sensory, such as vibrations, or
preferably a combination of any or all of the above.
Optionally, the detector could have different auditory, visual,
sensory, or different combinations to identify the source of the
detected breach, especially with more than one probe or more than
one type of probe. For example, LED's of different colors or
different sounds could be used. The alarm could further indicate
the seriousness of the breach. For example, when multiple probes
detect a breach, the volume of the alarm would increase to a higher
level.
As a further option, at least a portion of the exterior of the
inflatable balloon will be coated or impregnated with an
anti-microbial and/or adhesion resistant agent. Preferably, the
entire exposed surface of all components of the balloon will be so
coated or impregnated to inhibit colonization of the balloon by
bacteria or other microbes, and/or reduce possible accumulation of
food particles on the device. Suitable anti-microbial agents
include polyethylenetetrafluoride (PTFE), and antibiotics.
The present invention further provides methods for treating obesity
in a patient. The methods comprise introducing a gastric balloon
structure to the patient's stomach. An inflatable scaffold which
forms part of the balloon is then filled with an incompressible
fluid to provide a fixed support geometry. At least a portion of a
separate space-filling compartment is then filled at least partly
with a compressible fluid, typically a gas such as air, nitrogen,
or the like, within the remainder (if any) being filled with an
incompressible material, such as a liquid, gel, slurry, or the
like. In this way, the buoyancy of the balloon may be controlled
within the limits described above.
The methods of the present invention will usually further comprise
determining the size of the gastric cavity and selecting a gastric
balloon of proper size prior to introducing the balloon to the
stomach. Such size determination may comprise visually examining
the gastric cavity, typically under direct observation using a
gastroscope, but alternatively using fluoroscopy, ultrasound, x-ray
or CAT scanning, or any other available imaging method. An estimate
of the dimensions of the stomach and the size of the device can be
made by direct observation of the interior of the stomach
immediately prior to deployment. Alternatively, the dimensions of
the feeding stomach, which is generally larger than the resting
stomach, and the size of the device will be determined at an
earlier session where the patient has consumed or swallowed a
biocompatible filling medium, e.g., water, contrast medium, food,
etc. A sufficient amount of filling medium will be consumed so that
the imaging technique can detect full relaxation of the stomach
during feeding and estimate its dimensions and size.
Introducing may then comprise passing the gastric balloon in a
deflated configuration into the stomach through the same
gastroscope. Alternatively, the deflated balloon could be
introduced into the gastric cavity via an attachment to an
orogastric or nasogastric tube. The balloon will be oriented so
that the scaffold will open with curved geometry conforming to the
curve of the gastric cavity. Typically, the scaffold will be
released from constraint to self-expand or will be filled through a
removable inflation tube attached to the scaffold, where the
inflation tube may be removed after filling. The scaffold will then
be sealed or will more typically be self-sealing upon detachment of
the filling tube(s) to prevent loss of the inflating liquid medium.
Similarly, the space-filling compartment(s) will also typically be
filled through one or more inflation tube(s) removably attached to
the compartment(s), where the tube(s) are removed after the
compartment(s) have been filled with the desired medium, typically
a mixture of liquid and gas sources. Further, the external
bladder(s) will typically be filled through one or more inflation
tube(s) generally as described above for both the scaffold and the
space-filling compartment(s).
After all the principal structural components of the gastric
balloon have been inflated or otherwise expanded and the associated
inflation tubes released, any other anchors or tethers attached to
the balloon may also be released, leaving the balloon free to
"float" within the patient's stomach. By properly selecting the
ratio of liquid inflation medium to gas inflation medium, as
discussed above, the weight, distribution, and the buoyancy of the
gastric balloon will be such that the balloon rests within the
stomach without exerting undue pressure at any particular point,
thus reducing the risk of abrasions or other trauma to the stomach
lining. The inflated gastric balloon may be left in place for
extended periods of time, typically as long as weeks, months, or
even years.
After the balloon has been inflated and left in place, it may
become desirable to adjust the size and/or buoyancy of the balloon
for purposes of patient comfort, efficacy, or other reasons. To
perform such adjustments, the balloon will be transesophageally
accessed, typically using a gastroscope with suitable working tools
introduced therethrough. For example, the balloon may be grasped
with graspers and inflation tubes may be suitably attached or
docked to inflation ports on the balloon structure. Typically, the
inflation ports will all be located near the end of the gastric
balloon structure which is oriented toward the top of the stomach
so that they are readily accessed through the gastroscope. After
attachment with the inflation tube, the inflation medium can be
introduced and/or extracted, depending on whether the particular
structural component is to be enlarged, deflated, or have a
buoyancy adjustment. Optionally, an incising instrument could be
introduced through the gastroscope to penetrate and deflate any
filled compartment to reduce the overall volume of the device and
improve accommodation of the device. Typically, these compartments
are small to allow minor adjustments without jeopardizing the
integrity of the device itself.
In addition to adjusting the size and/or buoyancy of the gastric
balloon, it may become desirable or necessary to remove the balloon
completely. To effect such removal, the balloon will again be
accessed transesophageally, typically using a gastroscope. The
balloon will first be grasped or secured using a grasping tool.
Then, one or more surfaces of the balloon may be penetrated or
breached in order to release the contents of the balloon into the
stomach. The contents will be biocompatible gasses or liquids so
that release into the stomach will not be a concern. After the
contents of the compartments have been released, the balloon may
then be pulled through the patient's esophagus, typically by
pulling with the grasping tool. It may be possible to pull the
deflated gastric balloon through the working channel of the
gastroscope, but more often the balloon will simply be withdrawn
through the esophagus as the gastroscope is withdrawn. Optionally,
a sheath or other protective cover may be placed over the deflated
balloon in order to reduce the risk of trauma or injury to the
esophagus upon withdrawal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a gastric balloon constructed in
accordance with the principles of the present invention, shown
deployed in a stomach.
FIG. 2 is a cross-sectional view taken along line 2-2 in FIG.
1.
FIG. 3 is a top view of the gastric balloon of FIG. 1, illustrating
the inflation ports or nipples.
FIGS. 4A and 4B illustrate use of tools introduced through a
gastroscope for inflating and deflating the gastric balloon of FIG.
1, respectively.
FIGS. 5A through 5E illustrate a complete deployment protocol
according to the methods of the present invention.
FIG. 6 is a frontal view of a gastric balloon with an optional
material incorporated in a lattice configuration in the wall of the
device constructed in accordance with the principles of the present
invention.
FIGS. 7A through 7C are enlarged, peeled-back, cross-sectional
views of a portion of the multi-layered wall of the gastric balloon
of FIG. 6 constructed in different configurations in accordance
with the principles of the present invention.
FIG. 8 is a magnified cross-sectional view with an element in a
thin film configuration and in a lattice configuration in between
layers of materials used in construction of the balloon.
FIG. 9 is a frontal view of the portable detector with an example
of a failure display and auditory alarm constructed in accordance
with the principles of the present invention.
FIG. 10 illustrates an alternative balloon geometry in accordance
with the principles of the present invention, shown deployed in a
stomach.
FIG. 11 illustrates first embodiment of a self-expanding scaffold
for the balloon geometry of FIG. 10.
FIG. 12 illustrates a second embodiment of a self-expanding
scaffold geometry for a balloon having the geometry of FIG. 10.
FIG. 13 illustrates an inflatable scaffold suitable for use with a
balloon having the geometry of FIG. 10.
FIG. 13A is a cross-sectional view taken along line 13A-13A of FIG.
13.
FIG. 14 illustrates a gastric balloon in accordance with the
principles of the present invention including a pair of inflatable
space-filling compartments contained by an external sheath.
FIG. 15 illustrates a gastric balloon having two inflatable
space-filling compartments joined together by a spine
structure.
FIGS. 16-18 are flow diagrams illustrating several valving systems
suitable for inflating gastric balloons having multiple inflatable
compartments and optionally internal bladders in accordance with
the principles of the present invention.
FIG. 19 illustrates an exemplary structure for valving according to
FIG. 16.
FIG. 20, 20A, and 20B illustrate an exemplary structure for valving
according to FIG. 18.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 and 2, a gastric balloon 10 constructed in
accordance with the principles of the present invention comprises
an inflatable scaffold structure 12, four inflatable space-filling
compartments 14, and four inflatable external bladders 16.
Referring in particular to FIG. 2, the inflatable scaffold 12 has a
X-shaped cross-section and defines four generally axially oriented
channels or quadrants, each of which receives one of the four
inflatable space-filling compartments 14. The four inflatable
external bladders 16 are mounted over the inflatable space-filling
compartments 14, and the balloon 10 includes an upper cage 18 and
lower cage structure 20 which permit grasping of the balloon using
grasping tools, as will be described in more detail below. In its
deployed configuration, the gastric balloon 10 has a crescent or
curved shape which conforms to the interior shape of a gastric
cavity, with the upper cage structure 18 oriented toward the
esophagus E, the lower cage structure 20 oriented toward the
pyloric valve PV.
Referring now to FIG. 3, the inflatable scaffold structure 12 is
provided with at least one inflation port or nipple 22 while the
inflatable space-filling compartments 14 are provided with a
separate port 24 and the inflatable external bladders are provided
with a separate inflation port 26. Although not illustrated, the
scaffold, internal components, and external bladders could have
isolated, inflatable volumes therein, each of which would be
attached to a separate inflation tube. By "subdividing" the volume
of the various principal structural components, the risk of
accidental deflation of the balloon is further reduced.
As illustrated in 4A, after the gastric balloon 10 is introduced in
its deflated configuration into the gastric cavity, the inflatable
structural components could be inflated using a single inflation
tube 30 introduced through the gastroscope G, or orogastrically or
nasogastrically by itself or using an orogastric or nasogastric
tube. Typically, the upper cage 18 will be held by a grasper 32
which can selectively hold and release the gastric balloon 12
during inflation and subsequent deployment. Shown in FIG. 4A,
inflation tube 30 can be selectively coupled to any one of the
inflation ports 22, 24, or 26, and the desired inflation medium
introduced therethrough. Inflation tube 30 will be suitable for
delivering either liquid or gas inflation media, typically
including saline, water, contrast medium, gels, slurries, air,
nitrogen, and the like.
Usually, the inflatable scaffold structure 12 will be inflated
entirely with a liquid or other incompressible medium, such as a
gel, slurry, or the like. In contrast, the inflatable space-filling
compartments 14 will at least partly be inflated with air or other
gas. Often, however, the inflatable space-filling compartments will
inflated with a mixture of gas and liquid in order to control the
buoyancy of the balloon 12. Finally, the external bladders 16 will
typically be inflated with gas in order to provide a relatively
soft outer surface which can reduce trauma and abrasion.
The various structural compartments of the balloon may be made from
the same or different materials. Usually, the inflatable scaffold
structure 12 will be formed from a non-distensible (non-stretching)
material so that it may be inflated to become a relatively rigid
structure. Alternatively, or additionally, the structures may be
formed from stiffer materials and/or be reinforced to increase the
rigidity when inflated.
In contrast, the inflatable space-filling compartments 14 and the
inflatable bladders 16 may be formed in whole or in part from
softer elastomeric materials in order to allow inflation
flexibility, both in terms of size and density of the combined
inflation media. The elastic nature of the external bladders allows
the peripheral dimensions of the gastric balloon to be adjusted
over a significant range by merely controlling inflation volume.
Elastic inflatable space-filling compartments can allow the amount
of space occupied in the interior of the balloon to be adjusted,
for example to adjust the amount of volume filled by the balloons
within the quadrants defined by the scaffold structure 12.
Alternatively, the volume of incompressible fluid introduced into
non-elastic structures may be sufficient to control the volume
being occupied.
As an alternative to using a single inflation tube, each of the
inflation ports 22, 24, and 26 could be pre-attached to separate
inflation tubes. In such cases, after inflation of each structural
component is completed, the necessary inflation tube could then be
withdrawn through the gastroscope G, leaving the gastric balloon 10
in place.
Referring now to FIG. 4B, the balloon 10 can be deflated while
grasping the tip 18 of the balloon with grasper 32 through
gastroscope G using a blade structure 40 introduced through the
gastroscope. The blade structure 40 will preferably be used to make
one or more penetrations or breaches within each of the inflatable
components of the gastric balloon, including the inflatable
scaffold, the inflatable space-filling compartment(s), and the
inflatable external bladder(s)
Referring now to FIGS. 5A-5E, gastric balloon 10 is introduced to a
patient's stomach S using a gastroscope G introduced through the
esophagus E in a conventional manner. Standard procedures for
preparing and introducing the gastroscope are employed, including
checking for ulcerations in the esophagus and performing further
examination if warranted.
After introducing the gastroscope G, the size of the gastric cavity
within stomach S can be estimated and a balloon of an appropriate
size selected. The balloon 10 is then also introduced through the
esophagus E (orogastrically or nasogastrically) using an
appropriate catheter or optionally using the inflation tube(s)
which will be used to inflate the balloon. After the entire balloon
is confirmed to be in the stomach at a proper orientation,
typically using the gastroscope G, the various components of the
balloon 10 may be inflated as shown in FIGS. 5C and 5D. First, the
inflation tube 32 attached to the port which is coupled to the
scaffold 12 is inflated, typically using saline or other
incompressible liquid until the scaffold structure becomes
relatively rigid, as shown in FIG. 5C. During this inflation, the
balloon 10 is held by at least an inflation tube 32 and may
optionally be held by additional inflation tube(s) and/or a grasper
32.
After the scaffold 12 has been inflated, an additional syringe is
used to inflate the space-filling compartments through a second
inflation tube 33, as shown in FIG. 5D. The space-filling
compartments, again, will typically be inflated with a combination
of saline or other liquid and air or other gas in order to achieve
the desired density of the inflation medium therein. The external
bladders 16 will be inflated in a similar manner, typically using
air or other gas inflation medium only.
When it is desired to remove the gastric balloon 10, the balloon
may be deflated as previously discussed and removed through the
esophagus using a grasper 32 passing through the gastroscope G, as
shown in FIG. 5E. Typically, the balloon will be pulled out using
both the gastroscope and the grasper 32.
Referring now to FIG. 6, a gastric balloon 100 of a single
compartment constructed in accordance with the principles of the
present invention. As illustrated in FIG. 7A, the wall of the
balloon comprises at the minimum an outermost layer 102 and
innermost layer 104. The layers are manufactured by either dipping
a mold successively into solutions of different materials that dry
and cure or preferably by successive precision injections of
materials into a mold. Typically, the outermost layer 102 is made
of one or more materials, such as silicone rubber, selected
primarily for their non-abrasiveness, biocompatibility in the
stomach, and resistance to an acidic environment. Typically, the
innermost layer 104 is made of materials selected primarily for
their resistance to structural fatigue and impermeability to the
filling fluid. The inner layer 104 could have biocompatibility of a
shorter duration than the outermost layer. The two layers are
either bonded together to function as a single wall or left
unbonded such that the layers could slide by each other except at
certain attachment points.
Referring now to FIG. 7B, it may be desirable to enhance the
durability further by incorporating other structural elements in
the layers, such as a mesh 106 made of metal, polymer, or high
strength fibers, such as Kevlar, or the scaffold (not shown). The
mesh could constitute a separate layer as illustrated in FIG. 7B or
instead, could be embedded in one of the layers of material, as
shown embedded in layer 104 in FIG. 7C. A mesh 106 could inhibit
the propagation of a tear in the layers. Many of these materials
are radio-opaque which enables imaging clearly the entire shape of
the device using plain diagnostic X-ray radiography.
As illustrated in FIGS. 7B and 7C, in addition to layers of 102 and
106, one or more layers, 108 and 110, of materials selected for the
optimal balance of biocompatibility, impermeability, rigidity,
shear resistance among other criteria could be added to enhance the
structural performance characteristics of the device further.
Referring now to FIG. 7B, layers, 108 and 110, could also represent
other materials incorporated to enable or enhance certain
functional performance characteristics of the device. Instead of
disposing the detection marker in the enclosed volume of the
balloon, the marker may reside in between any of the layers either
in a thin film or in a lattice configuration. It is also possible
to dispose the marker in the open spaces in the mesh (not shown). A
thin film or coating of a substance that is detectable upon
excretion or regurgitation by the patient, such as a dye, would be
released into the stomach in the event the integrity of the layer
external to the substance is compromised. For example, the
substance that forms thin film is released into the stomach when a
breach, such as a tear, occurs in layer 102.
Referring now to FIG. 7C, as an optional configuration, different
substances, 108a and 108b, may be placed in between different
layers so that the particular layer which failed may be identified
based on what is detected. For example, if 108a were detected in
the excrement, one would deduce that layer 102 has been breached
but layer 110 has not. This would constitute a situation where
medical assistance can be provided on an elective basis. Once 108b
is detected in the excrement, one would deduce that at the minimum,
layers 108 and 110 have both been compromised leaving only layer
104 as possibly the last line of defense. This would represent a
medical emergency where the device should be removed before
complete failure.
Another failure detection system comprises a chemical substance and
a chemical vapor detector, an "electronic nose," that detects a
change in vapor concentration of the substance, its metabolite, or
any of its reaction products. Optionally, it includes at least one
other chemical or biochemical that reacts with the chemical, its
metabolite, or any of its reaction products to enhance the
sensitivity and/or specificity of detection. When used in
conjunction with a biomedical device, the system represents a
method to detect early potential failure or malfunction involving a
structural breach. While this invention is described being used in
conjunction with a gastric balloon, it does not exclude use in
other biomedical devices where signaling a potential failure or
malfunction, especially those potentially leading to a catastrophic
loss, is desired.
Referring again to FIG. 6, the gastric balloon 100 includes a
chemical substance in a lattice configuration 110 incorporated in
the wall of the balloon. The chemical substance could be naturally
occurring, synthetic, or made by the human body. As magnified in
FIG. 8, the chemical substance can be disposed in a fine lattice
configuration 110 and/or in a thin film configuration 112 in the
wall of the balloon in between two or more layers, e.g., outermost
layer 102 and innermost layer 104. The chemical substance can be
also disposed in any enclosed space in the device (not shown)
After the balloon 100 is deployed in the stomach, the chemical
substance comes in contact with and is released into the
surrounding tissue and body fluids upon a breach in the integrity
of the wall. As illustrated in FIG. 8, the chemical substance 112
comes in contact with and is released when there is a tear in the
outermost layer 102 of the balloon wall. After release, the
chemical substance, either in its stable form, its metabolite, or
reaction product is eventually secreted or excreted into the bodily
fluids. The chemical substance, its metabolite, or reaction product
is sufficiently volatile in its secreted or excreted form so that
the change in vapor concentration of the secreted or excreted form
is significant enough to be detected by a chemical vapor sensor.
The chemical vapor detector is based on either the natural
olfactory sense or the commercially available technology of
so-called "electronic nose", with which certain chemicals can be
detected at levels from parts per million to parts per billion.
Referring now to FIG. 9, the sensor, power source, and electronic
circuit is enclosed within detector 120. The detector 120 is
preferably powered by batteries and portable enough to be worn on a
wristband or belt or can be placed conveniently near the toilet.
Upon sensing the chemical substance, its metabolite, or a reaction
product, the detector will alert the patient to seek medical
assistance. The alarm could be visual, such as lit or blinking
LED's 122 and 124, and can designate different levels of urgency
depending on what was detected. For example, a lit LED 122 could
indicate that chemical substance 112 in FIG. 8 has been detected.
It can be deduced that layer 102, external to 112 has been
breached. Since there are still more than two layers to breach
before complete breach of the balloon wall, medical assistance can
be provided on an elective basis. In the same fashion, a lit LED
124, could indicate chemical substance 110 has been detected, and
therefore layer 106 external to 110 has been breached. Since only
layer 104 remains as the last barrier to complete breach of the
wall and when that occurs cannot be predicted, the device needs to
be removed on an emergent basis. A power light 121 is provided to
assure the device is on.
Shown in FIG. 9, the alarm 126 could also be auditory, such as
beeping sounds, or sensory, such as vibrations, or preferably a
combination of any or all of the above. Optionally, the detector
could have different auditory, visual, sensory, or different
combinations to identify the source of the detected breach,
especially with more than one chemical substance used. The alarm
could further indicate the seriousness of the breach. For example,
when breaches are detected, the volume of the alarm would increase
to a higher level.
Optionally, the system could be improved by subjecting the
chemical, its metabolite, or reaction product to certain physical
perturbation, such as heat or sonic waves or a toilet flush, such
that the vapor concentration is altered. Alternatively, the system
could be improved through a reaction where the chemical substance,
its metabolite, or reaction product is mixed with other chemicals
or biochemicals, including solvents, resulting in a product whose
vapor concentration has changed enough to be readily detected by a
sensor.
Optionally, detecting the change in vapor concentration of more
than one of the chemical substance, its metabolites, or its
reaction products could increase the sensitivity and/or specificity
of the detection system.
Another failure detection system comprises two electrical probes,
wireless transmitter, and a wireless detector. While this invention
is described using radio frequency as the signal transmission of
choice, it does not exclude other carrier waves, such as light or
sonic, or via physical properties, such as magnetism or
temperature. When used in conjunction with a biomedical device, the
system represents a method to detect early potential failure or
malfunction involving a structural breach. When used in conjunction
with a biomedical device, the system represents a method to detect
early potential failure or malfunction involving a structural
breach. While this invention is described being used in conjunction
with a gastric balloon, it does not exclude use in other biomedical
devices where signaling a potential failure or malfunction,
especially those potentially leading to a catastrophic loss, is
desired.
Referring now to FIG. 6, the gastric balloon 100 includes two
electric probes. Probe 130 is on the external surface in contact
with the surrounding tissues, body fluids, and contents of the
stomach. The lattice configuration 110 provides the second probe
incorporated in the wall of the balloon. The probe material could
be any metal, polymer, fiber, or combination thereof, with or
without any coating that can generate an electrical charge or
enable flow of electric current when in contact with the stomach
contents. The probes are connected electronically to the wireless
transmitter 140, but are separated from each other by at least one
layer of non-conductive material in the balloon wall. The
transmitter can be a simple wireless signal generator triggered by
an electric current or preferably is a transponder using the
well-established RFID technology, i.e., produces a wireless signal
in response when triggered by an interrogating signal. In the
intact state, 130, 110, and 140 represent an open electrical
circuit and the transmitter is enabled to transmit a base
signal.
As magnified in FIG. 8, the internal probe can be in a fine lattice
configuration 110 or in a thin film configuration 112 in the wall
of the balloon in between, at the minimum two layers, an outermost
layer 102 and innermost layer 104. The internal probe can be also
disposed in any enclosed space in the device (not shown). In the
configuration described in FIG. 8, probes 130 and 110 and
transponder 140 represent one open circuit and probes 130 and 112
and transponder 140 represent a second open circuit. Each open
circuit enables the transponder to transmit a base signal.
After the balloon is deployed in the stomach, the external probe
130 is in contact with the surrounding tissue and body fluids and
stomach contents. Upon a breach in the integrity of the wall, such
as a tear in the outermost layer 102 as illustrated in FIG. 8, the
leakage of physiologic fluid or stomach contents with electrolytes
into the tear forms a salt bridge that closes the circuit formed
probes 130 and 112 and transponder 140. Once the circuit is closed,
a toggle is switched in the transponder, which will be enabled to
transmit a "layer 102 breach" signal. Tears through layer 106 in
the balloon wall will allow leakage of physiologic fluid or stomach
contents with electrolytes into the tear forming a salt bridge that
closes the circuit formed probes 130 and 110 and transmitter 140.
Closing this circuit switches another toggle in the transponder,
which will be enabled to transmit a "layer 106 breach" signal.
FIG. 10 illustrates an alternative crescent-shaped balloon geometry
suitable for use in the gastric balloons of the present invention.
Gastric balloon 200 has a generally flat or truncated upper surface
202 which is positioned adjacent to the esophagus E. A lower end
204 is also generally flat or truncated. These flat ends 202 and
204 are distinguishable from the more tapered ends of the prior
gastric balloon embodiments. Although illustrated schematically as
a single unit or structure, it will be appreciated that the balloon
200 will usually comprise multiple independently inflatable
space-filling compartments and optionally further comprise external
inflatable bladders. The geometry shown in FIG. 10 is intended to
illustrate the peripheral shape of the device including all
components.
Referring now to FIGS. 11-15, gastric balloon structures having the
geometry of balloon 200 in FIG. 10 may be deployed using a number
of different expandable scaffolds. For example, as shown in FIG.
11, the balloon structure 200 may include an external
"exo-skeleton" 210 comprising a spine 212 and a plurality of ribs
214 extending laterally from the spine. The spine 212 and ribs 214
are preferably made from elastic components, such as nickel
titanium alloys or other super elastic materials, permitting them
to be folded and compressed to a small width for introduction. The
scaffold will then be deployed by releasing the scaffold from
constraint after it has been positioned within the stomach.
The balloon 200 may also be mated with an end cap 220. The end cap
220 may include, for example, a plurality of interlaced panels
which can be folded down to a low profile configuration for
delivery. The panels may be composed of elastic polymers, shape
memory metals, shape memory polymers, or the like. The use of end
caps 220 is particularly useful when the balloon will itself
comprise a single compartment. The end cap will prevent accidental
passage of the balloon through the pylorus even upon rapid
deflation of the balloon.
The balloon 200 may also be mated to an inflatable scaffold 230,
which may be conveniently formed into the shape of a saddle, as
shown in FIGS. 13 and 13A. The balloon 200 may comprise one, two,
or more separate inflatable compartments. Each of these
compartments, as well as the inflatable scaffold 230, will require
separate inflation, preferably using one of the valving mechanisms
described hereinbelow. The inflatable scaffold 230 could have other
configurations as well, such as being in the form of a lattice with
a central inflatable spine and multiple arms disposed laterally
outwardly about the remainder of the balloon 200.
Referring now to FIGS. 14 and 15, the balloon 200 may comprise
first and second internal inflatable compartments 240 and 242
having an external sheath or exoskeleton 244. The sheath 244 may
be, for example, a non-distensible outer tubular structure having
the desired crescent geometry, with the inflatable compartments 240
and 242 disposed therein. Alternatively, the exoskeleton could
comprise a mesh, fabric, or other flexible containment member which
holds the separate inflatable compartments 240 and 242 in place
relative to each other. At least a portion of the exoskeleton 244
could be made to be non-collapsible in order to prevent accidental
passage of the balloon through the pyloric valve in case of
unintended deflation of both of the inflatable compartments 240 and
242.
The compartments 240 and 242 could also be held together by a spine
element 250, as shown in FIG. 15. The balloons would be attached to
the spine, optionally by heat sealing or adhesives, usually one or
more fasteners 252, such as adhesive straps, are provided about the
periphery of the inflatable compartments 240 and 242 to hold them
together after deployment. The spine 250 can also optionally be
used to receive and deploy inflation tubes, as described in more
detail below.
Each of the balloons 200 described above will be provided with a
valve mechanism or assembly to permit selective inflation with
liquid fluids, gaseous fluids, or a combination thereof. If only a
single inflatable compartment is utilized, the valving mechanism
could be simply a one-way valve having a connector for releasably
connecting to an inflation tube. For example, the inflation tube
could be connected to the connector on the valve prior to
introduction of the balloon in the patient's stomach. After
introduction, the inflation medium could be introduced through the
tube, and the tube detached and removed after inflation is
complete. Optionally, the inflation tube could be introduced later
for reinflation of the balloon if desired.
When two or more inflatable compartments, and optionally external
bladders, are provided, the valve assemblies of the present
invention will preferably provide for selectively delivering
inflation medium to individual inflation ports on each of the
inflatable compartments, external bladders, and optionally
inflatable scaffolds. Inflation valves will usually comprise a
one-way valve structure, such as a flap valve or a duckbill valve.
The valves associated with each compartment will be arranged to
permit manipulation of an associated inflation tube so that the
valve is in line with an inflation port on the inflation tube to
permit delivery of inflation medium.
In FIG. 16, for example, a first one-way valve 300 can be mounted
on a wall of a first balloon compartment and a second one-way valve
302 can be mounted on the wall of a second balloon compartment. By
then arranging the two valves in opposite directions along a common
axis, an inflation tube 304 having a rotatable inflation port 306
can be disposed between the two valves. Then by turning the
inflation tube, the first valve 300 or the second valve 302 may be
selected to deliver inflation medium through the single inflation
tube 304.
Alternatively, as shown in FIG. 17, a first inflation valve 310, a
second inflation valve 312, and a third inflation valve 314, each
of which is associated with a respective balloon compartment, may
be axially arranged so that a single inflation tube 316 may be
translated to successfully access each of the one-way valves 310.
In this way, each of the associated balloon compartments may be
selectively inflated and reinflated by simply axially translating
the inflation tube 316.
As a further alternative, as shown in FIG. 18, a single inflation
tube 320 having multiple inflation ports 322, 324, and 326 may be
disposed next to a linear array of balloon compartments and one-way
inflation valves 330, 332, and 334. In this way, instead of axially
translating the inflation tube 320, the valves can be selected by
rotating the tube so that only a single inflation port is aligned
with a single one-way valve at one time.
It will be appreciated that the above-described valve mechanisms
and assemblies may be constructed in a wide variety of ways using a
wide variety of one-way valve structures. For the purposes of the
present invention, it is desirable only that the valve structures
permit selective introduction of an inflation medium to individual
balloon compartments using a single inflation tube. It will also be
appreciated that more than one valve may be used in series (not
shown) in place of a single valve to reduce further the potential
for leakage of the filling media.
A first specific structure for implementing the inflation assembly
of FIG. 16 is shown in FIG. 19. The inflation tube 304 having
inflation port 306 is disposed between a wall 350 of a first
balloon and a wall 352 of a second balloon. The first one-way valve
300 is positioned through the first wall 350, and the second
one-way valve 302 is positioned through the second wall 352. Those
valves are shown as duckbill valves. As shown in FIG. 19, the port
306 is aligned with the first one-way valve 300 so that
introduction of a pressurized inflation medium through lumen 305 of
the inflation tube 304 will open the duckbill valve and allow
inflation medium to enter the first balloon. By then rotating the
inflation tube 350 by 180.degree. so that it is aligned with the
second valve 302, inflation medium can be similarly delivered to
the second balloon.
A specific valve system constructed generally as shown in FIG. 18
is shown in FIGS. 20, 20A and 20B. The inflation tube 320 is
rotatably disposed within an outer tube 360 which passes between
walls 362 and 364 of first and second inflatable compartments,
respectively. The distal-most one-way valve 334 is disposed in a
first radial direction on the outer tube 360, and the next inner
one-way valve 332 is offset by 90.degree.. The ports 362 and 364 on
the inflation tube 320 (FIGS. 20A and 20B not illustrated) will be
arranged so that in a first rotational position one port 362 is
aligned with one-way valve 332 and in a second rotational position,
a second port 364 is aligned with one-way valve 334. At no time,
however, is more than one inflation port aligned with more than one
one-way valve on the outer tube 360. Thus, by rotating inflation
tube 320, individual inflatable compartments can be inflated.
While the above is a complete description of the preferred
embodiments of the invention, various alternatives, modifications,
and equivalents may be used. Therefore, the above description
should not be taken as limiting the scope of the invention which is
defined by the appended claims.
* * * * *